This natural marble cave is one of only five national monuments in Oregon.

A tourist attraction founded around a slumping cabin.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

A sculpture of a salmon swimming through a brick building.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

An extraordinary mixture of natural beauty and man-made phenomena.

A giant Troll lurks under one of Seattle's oldest bridges.

This expansive bridge in the Canadian wilderness was originally just built for friends.

"Girl in a Wetsuit" is what happens when a sculptor has to find a way around a 100 year old copyright.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.

The original home of the Lego has a huge amusement park dedicated to the iconic plastic toy.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

An enormous playhouse designed to look like 21 stacked Lego bricks, with another 25 million colorful Legos inside.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

The narrow passages will challenge even the bravest driver.

This mysterious, medieval cathedral remains unbuilt but fiercely protected.

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .

A stunning architectural yet functional feat, towering over Oslo.

The world's first and only escalator for lazy bicycles and their daunted riders.

A naturally occurring tunnel in this Nordic mountain makes it look like it's been shot.

World's strongest whirlpool.

At the very tippity-top of Europe is a cliff from which you can view the midnight sun.

Home to three historic ships from the age of Vikings.